1. Field of the Invention
This invention relates generally to a video projector and is directed more particularly to a color video projector which has three cathode ray tubes for producing three primary color images of red, blue and green colors separately.
2. Description of the Prior Art
There is known a color video projector of the projection type for magnifying a video image, for example, a color image on a color cathode ray tube and projecting it upon a screen.
FIGS. 1, 2 and 3 show a typical prior art example thereof in which red, green and blue primary color images are obtained separately and then projected through two lens devices to form a color image, and it is called a two-eyed three-tube type projector.
In the figures, numerals 1R, 1G and 1B represent color cathode ray tubes for producing red, green and blue primary color images, respectively, which are disposed within a projector body 2, for example, as shown in FIG. 2. In the figures, numerals 3 and 4 denote lens devices, 5 a dichroic mirror and 6 a screen, respectively.
In order to minimize as much as possible the space occupied by the projector, including the screen 6, and to make the adjustment of the optical system unnecessary, it is sufficient that the screen 6 be mounted, for example, on a part of the projector body 2 as illustrated. This arrangement will require a mirror 7 because a color image cannot be projected directly upon the screen 6.
The mirror 7, for reasons of the related optical distance or the like, should be mounted on a mounting board 8 and positioned outside the projector body 2 such as in the manner illustrated. Thus, when the projector is not being operated, it is desirable for the mirror to be, for example, housed or replaced in the projector body 2 to avoid damage and to give a pleasing appearance.
With the above prior art projector, when the projector is used, it is necessary that the mounting board 8 be withdrawn from the projector body 2. In this case, it is necessary that the mounting board 8 be moved outwards in the direction indicated by an arrow A in FIG. 3 and then rotated in the direction indicated by an arrow B. At this time, if the mounting board 8 is erroneously rotated before it is moved outwards, a lower end edge 8a of the mounting board 8 abuts against the upper end edge of a front panel 2a of projector body 2. Thus, there occurs the objectionable features that the front panel 2a and/or a movable arm 18, which is pivoted on a support 16 fixed to the board 8 at a pivot pin 17, are damaged.